Maximum security lock assemblies

ABSTRACT

A maximum security lock assembly adapted for mounting on a door within a door frame, comprised of an armor plate of toolresistant alloy steel having an integral frusto-conical protrusion extending outwardly therefrom, on the interior of which is fixed a pin tumbler lock with a cylindrical plug or core which is released for rotary movement upon the insertion of the properly fitted key into its keyhole. An oscillating crank connected to the rotary plug actuates a bolt mechanism which is selectively engageable with apertured lugs on a strike on the door frame which extend into the field of movement of the locking bolts when the door is in closed position. An opening of restricted area in the outer wall of said protrusion permits the insertion of said key into the keyhole of the lock and the rotation thereof while leaving concealed the main outer face of the lock and especially the portions thereof most vulnerable to picking and drilling of the lock assembly. The screw and bolt fasteners for the complete lock assembly including the components thereof, are hidden, and a shield of tool-resistant alloy surrounds the connections from the lock to the bolt actuating mechanism to prevent the disabling of the locking assembly at this portion thereof. The armor plate and protrusion extending therefrom which is resistant to the operations of drills, wrenches and jimmys thereon may be duplicated on the inner side of the door to secure the lock assembly against operation without a proper key on the inner side of the door as well as on the exterior thereof.

United States Patent [1 1 Kent et al.

[451 Oct. 30, 1973 MAXIMUM SECURITY LOCK ASSEMBLIES [76] Inventors:'Robert W. Kent, PO. Box 4311,

. Normandy Branch, 1940 Biarritz Drive, Miami Beach, Fla. 3314];

Avenue, Andover, Mass. 7"

[22] Filed: June 29, 1972 [21] Appl. No.2 267,474

US. Cl 70/104, 70/406, 70/417,

70/448, 70/DIG. 60 {51] Int. Cl E05b 9/04 [58] Field of Search 70/103,104, 134, 70/393, 405, 406, 417, 44 8, DIG. 57, DIG. 60; 292/340 [56]References Cited UNITED STATES PATENTS 2,225,663 12/1940 Sega]; 70/1041,512,939 10/1924 Ledim 70/134 3,550,411 12/1970 Neary et al.. 70/3702,683,054 7/1954 Earman 292/340 3,541,822 11 1970 Murphy 70/421 12/1934Falk 70/103 Primary Examiner-Albert G. Craig, Jr. Attorney-SamuelLebowitz [57] ABSTRACT A maximum security lock assembly adapted formounting on a door within a door frame, comprised of 1 Robert W. Kent,Jr., 23 Wolcott W an armor plate of tool-resistant alloy steel having anintegral frusto-conical protrusion extending outwardly therefrom, ontheinterior of which is fixed a pintumbler lock with a cylindrical plug orcore which is released for rotary movement upon the insertion of theproperly fitted key into its keyhole. An oscillating crank connected tothe rotary plug actuates a bolt mechanism which is selectivelyengageable with aper tured lugs on a strike on the door frame whichextend into the field of movement of the locking bolts when the door isin closed position. An opening of restricted area in the. outer wall ofsaid protrusion permits the insertion of said key into the keyhole ofthe lock and the rotation thereof while leaving concealed the main outerface 'of the lock and especially the portions thereof most vulnerable topicking and drilling of the lock assembly. The screw and bolt fastenersfor the complete lock assembly including the components thereof, are,hidden, and a shield of tool-resistant alloy surrounds the connectionsfrom the lock to the bolt actuating mechanism to prevent the disablingof the locking assembly at this portion thereof. The armor plate andprotrusion extending therefrom which is resistant to the operations ofdrills, wrenches and jimmys thereon may be duplicated on the inner sideof l the door to secure the lock assembly against operation without aproper key on the inner side of the door as well as on the exteriorthereof.

23 Claims, 10 Drawing Figures PATENIEDUEI 30 1915 3.768.284

' sum 2 BF 2 FIG.8 2

m IN] mllllll MAXIMUM SECURITY LOCK ASSEMBLIES. This invention relatesto a substantially burglar-proof lock assembly for mounting on the doorsof residences,

warehouses, industrial buildings, or any other enclosures, in order toprevent unlawful entry therethrough.

It is the object of the present invention to provide a door closurewhich is substantially burglar-proof by incorporating structuralfeatures in the lock assembly on the door in cooperation with a ruggedlymounted strike on the frame.

It is another object of the invention to provide lock componentsand toarrange for the disposition of them, which renders virtually impossible,or at least ex tremely difficult, for the lock to be picked, jimmyed,multilated or destroyed with tools such as drills, wrenches, pliers,crowbars and the like, and which, upon simple inspection, woulddiscourage a potential burglar from tapering with the lock.

It is a further object of the inventionto provide for a lock assemblywhich may be produced economically, which is rugged in construction andeasy to install, so that the wide adoption of such would have a salutaryeffect on the reduction of burglaries and the attendant high costs tothe individual victims as well as the general public, which areoccasioned thereby.

Other objects and purposes will appear from the detailed description ofthe invention following hereinafter, taken in conjunction withtheaccompanying drawings, wherein FIG. 1 is a front elevation .of the lockassembly mounted on a door hinged within a door frame viewed from theinterior thereof;

FIG. 2 is a horizontal sectional view along line 2-2 of FIG. 1;

FIG. 3 is a front elevation of the lock assembly mounted on the doorviewed from the exterior thereof along line 3-3 of FIG. 2;

FIG. 4 is a perspective view of the strike plate mounted on the doorframe opposite the door hinges, parts of which strike plate are shown inFIGS. 1 and 2;

FIG. 5 is a vertical sectional view along line 55of FIG. 1;

FIG. 6 is anenlarged view of the outer face of the lock assembly in thevicinity of the keyhole, along line 6 -6 of FIG. 5;

FIG. 7 is a view of the outer face of the cylinder lock along line 7-7of FIG. 5;

FIG. 8 is a front view of the key which is adapted to be inserted in thekeyhole shown in FIG. 6;

FIG. 9 is a top view of the key shown in FIG. 8; and

FIG. 10 is an end view of FIG. 9.

In the drawings is shown a door D mounted within a frame F,F' which, forthe purpose of illustration, is shown as an inside opening door mountedon hinges H on one side thereof having the lock assembly C mounted onthe other side thereof cooperatingwith the strike S mounted on the stileF of the frame. As explained below, the lock assembly also may beapplied to outside opening doors as well as to sliding doors.

The drawings illustrate a maximum security lock assembly which requiresthe operation by a key on both the outside and inside of a door closure.Thus, in FIG. 2 the lock assembly comprises an armor plate 10 having afrusto-conical protrusion extending outwardly therefrom and terminatingin the flat external portion 12 in which is disposed the keyhole opening13, described in greater detail below.

The armor plate 10, of any suitable tool-resistant steel alloy, ismounted on the outside face of the door by means of a plurality of bolts14 which are affixed by welding, brazing, soldering, etc. to theinternal face of the armor plate 10 and which extend through boredopenings 14' in the door into the interior of lock casing C, which ismounted onthe internal face of the door as shown in FIGS. 1, 2 and 5.

A cylinder lock 15, containing a plurality of longitu' dinally arrangedpin tumbler units 16, is fastened on the interior of the frusto-conicalprotrustion 11 by bolting with the usualpair of bolts, welding, brazing,soldering, etc. No evidence of the mounting appears on the outer face ofthe protrusion. This is accomplished by affixing the usual pair offastening bolts of the type disclosed in U.S. Pat. No. l,579,l39,Mar.30, 1926, to the inner face of the flat external portion 12 of thefrusto-conical protrustion similarly to the bolts 14 on the inner faceof the armor plate. The cylinder lock with diametrally opposed bores areslid onto the fastening bolts, and thereafter locking nuts, with orwithout additional lock washers, are applied to the free ends of thefastening bolts to secure. the cylinder lock tightly against the innerface of the armor plate and protrustion therein or against spacers 61.Lock constructions of this type are well known in the art, asexemplified by U.S. Pat. No. 1,967,042, July 17, 1934. Such locks aregenerally provided with a rotary plug or core 17 extending therethrough,which, upon the insertion of a properly fitted key into the keyhole slotat the outer end of the plug or core, results in the release of thelatter for rotary movement. An additional measure. of security may beattained by the use of cylinder locks of multiple rows of pin tumblersof the type disclosed in U.S. Pat. Nos. 1,707,922, Apr.2, 1929, and2,836,973, June 3, 1958. In such locks, the pin tumbler units 16 aresupplemented by additional pins 16a and 16b of pin tumbler unitsdisposed in planes at an angle of approximately 30 relative to the planecontaining the main operating drivers 96 with their compression springs96', (FIGS. 5 and 7). The back-up drivers 97 and 98, with theircompression springs 97 and 98', respectively, in the rows flanking thedrivers 96, render impossible a complete turning of the lock plug 17when the lock is picked, since upon the turning of the plug 20 to 30either way, the back-up tumblers shoot into the plug holes and re-lockthe plug. Ten back-up tumblers in each back-up row are sufficient whentwelve are disposed in the row of main drivers in alignment with the keyslot, as shown in FIG. 5. The proper key cannot be pulled out at eitherof the radial points because there is no hole for the reception of theinner pair at these points. If anyone were to succeed in picking thecylinder plug, either to the left or right, the turning of the plugapproximately 30 would result in the outertumblers dropping into theplug, thus locking the cylinder in an 11 oclock or 1 oclock position,and requiring that it be picked all over again to release the plug.

.A tongue or tailpiece l8, generallyof steel alloy of flat rectangularcross-section, is connected to the inner end of the core to impartrotary movement to an oscillating crank 19 at the outer end of thetailpiece 18 for actuating the lock mechanism described in greaterdetail below.

The inclination of the frusto-conical portion 1 I of the armor plate 10is such, that wrenches, pliers and similar tools are incapable ofgrasping the portion 11, so that wrenching the lock from the assembly isrendered impossible. This inclination may be of the order of 45 relativeto the plane of plate 10. Furthermore, the number of pin tumbler units16 within the lock may be increased to as many as twelve, as describedabove, in order to render the picking thereof more difficult than is thecase with conventional locks of this type which generally are providedwith five or six pin tumbler units, and the security of the lock may beenhanced by using pins of drill-proof steel alloy. Also, the outer faceof the lock is housed within the protrusion 11 and, because of thefrusto-conical formation, is displaced from, the exterior thereof, sothat the manipulation of alock-picking tool is rendered difficult. Thespacing of the outer face of the cylinder lock within the protrusion maybe controlled easily by the provision of'washers on the above-mentionedconventional pair of fastening bolts which, of course, are accessibleonly from the inner face of the armor plate. The gap between the end ofthe lock and the keyhole opening in the outer plate 12 may be filledwith one or more layers 61 of toolresistant steel or other alloys, sothat the drilling of the lock and/or entry of tools thereinto areeffectively blocked.

The mounting of the cylinder lock on the interior of the protrusion 11by bolting, soldering or welding, eliminates the mounting collars whichare usually used for the mounting of such and which provide a point ofentry for prying and jimmy tools. Also, the absence of any mountingscrews or bolts on the outer face of the armor plate 10 rendersimpossible the jimmying of the lock at these points.

The lock case C mounted on the internal side of the door is affixedthereto by means of the bolts 14 which extend through the door D andthrough openings 24 in the supporting plate 60 and rear wall 30 of lockcase C, and which are tightly fastened together by means of nuts 28. Themetallic case C may be formed of square or rectangular outline havinghorizontal lateral walls 31,31 projecting from the upper edges of backwall 30 and vertical lateral walls 32,32 extending from the back wall 30and forming a continuous boundary thereon in conjunction with walls31,31.

The lock case contains a bolt actuating mechanism comprising plate 33which is vertically reciprocable within the case adjacent to the backwall 30, and which mechanism terminates in coaxially disposed bolts35,35 which are vertically movable adjacent rectangular slots 36 in thecase which overlie the door frame F (FIGS. 2 and 3).

The vertical movements of the bolts 35, 35' from their alternatepositions into and out of intersecting relationship with the slots, arecontrolled by the actuating mechanism 33 which includes camming surfaceswhich are responsive to the oscillating movements of the crank 19, whichis rotated by the tailpiece 18 connected to the inner end of the plug 17of the cylinder lock 15. This actuating mechanism does not constitutepart of the instant invention and such may assume any desired form knownin the art. US. Pat. Nos. 1,162,406, Nov. 30, 1915; l,2l5,470, Feb. 13,i917; 1,924,627, 'Aug. 29, 1933; and 2,042,026, May 26, 1936, areillustrative of many in the art which disclose such mechanisms.

A detachable cover is provided for the open face of the lock case Cdefined by the free edges of walls 31,31, 32 and 32. A lateral wall 40extends rearwardly from one edge of cover 20 adjacent to wall 32 and isbent inwardly to form wall portion 41 against the exterior face of backwall 30 which overlies the door frame F. Rectangular slots 36 in wallportion 41 are coincident with slots of the same dimensions in wall 30and countersunk openings in wall 41 receive flatheaded screws 66 forfastening the cover 20 to wall 30 of the lock case. The upperand loweredges of the cover 20 are channeled at 42,42 to slide within tracks 43,43 at the outer edges of walls 31,31, respectively. A flange 67 is benttransversely from wall 32 to seat and conceal the free edge of cover 20in the closed position of the lock case when the screw fasteners 66interconnect the cover and the case at the inner wall portion 41. Theconstruction of the lock case and cover therefor prevents thedestruction thereof by crowbars or other prying tools.

The slots 36 in the lock case are adapted to receive the lugs 53 whichproject from the face 51 of the strike S which is affixed to the stile Fof the door frame. The lugs 53 are fitted with aligned apertures 55 sothat when the lugs53 enter the slots 36 in the lock case, the openings55 are in alignment with the line of travel of bolts 35,35 when the dooris in closed position. The door may be locked by reciprocating the boltsadjacent to the bolts 36 so that they engage the cylindrical apertures55 in the lugs 53 to effect a secure locking of the door within theframe. The turning of the lock and the movement of the bolts from beyondthe field of slots 36 results in a movement of the bolts from theopenings 55 in the lugs 53 so that the door may be opened by knob K.

The mounting of the strike S is effected by means of screw fasteners 56of substantial lengths of approximately two and one-half inches orlonger so that the introduction of such fasteners into the twotransverse plates 51 and 52 of the strike, results in the penetration ofthese fasteners not only into the frame, as is conventionally done, butalso into the structural timbers T backing up the frame, so that aprying of the strike from the frame with a crowbar or similar tool isrendered impossible.

As may be seen from FIGS. 1 to 4, when the door is in closed positionand locked, the screw and bolt fasteners of the entire assembly, namely,14,66 and 56,

are invisible so that tampering with such, to effect an illegal opening,is rendered impossible.

In order to attain maximum security for the lock assembly, the cover 20for the lock case, on the internal side of the door, is fabricated oftool-resistant metallic alloy material and is formed with afrusto-conical pro- I trusion 21 is substantial alignment with theprotrusion 11 on the outside of 'the door. A pin tumbler lock 65,similar to lock 15, containinga large number of pin tumbler units 67,with rows of backup tumbler sets 67 and 67", is affixed to the interiorof the protrusion by bolting, soldering, brazing or welding, and theinner end of the rotary plug 68 is connected with an oscillating crank69 which is operative in the same range of movement as is theoscillating crank 19 controlled by the lock 15 to actuate the slidingplate 33 and the bolts 35,35 to effect the engagement and disengagementof the bolts with the apertures 55 in the lugs 53 of the strike S whenthe door is in closed position.

The flattened exterior portion 22 is provided with a restricted opening63 which permits the insertion of the key into the keyhole at the outerend of the lock 65 and the rotation thereof while concealing the outerface of the lock and particularly the area immediately beyond the shankof the key which effects a lifting of the pin tumblers to release theplug for rotation whereat drilling tools are introduced to effect thedestructionof the lock mechanism.

In this construction as well, a space is presented between the outerface of the lock 65 and inner face of the plateau 22 of the protrusionwhich renders difficult the introduction of lock picking tools'into thekeyhole. This space may be filled by one or more layers 71 of steelalloys which are especially resistant to penetration by drilling orother destructive instruments.

This arrangement renders the disabling of the lock as difficult from theinner side of the door as it is from the outer side of the door, but theintroduction of the proper key into the keyhole effects a locking and anunlocking of the door by the second oscillating crank 69 which controlsthe bolt actuating mechanism in the same manner as does the firstoscillating crank H.

In FIG. 6 is shown the outer face of the armor plate 11 at the flattenedportion 12, on an enlarged scale. The outer face 15' is visible throughthe opening 13 in the armor plate for the insertion of the key into theslot 75.

In F I68. 8 to is illustrated a specially designed key for the reliableoperation of the safety lock 15 which is comprised of a shank 80 groundspecially along one of its edges 81 corresponding to the arrangement ofthe pin tumbler units in the lock. The key is recessed at the portion 83between the handhold 82 and the shank 80, so that following theinsertion of the key into the keyhole slot with the edge 81 coincidentwith the end 76 of the keyhole slot, the plug 17 may be rotated toeffect the movement of the tailpiece 18 and the oscillating crank 19connected thereto. In order to reenforce the key, propulsion pins 85 areprovided on the inner face of the handhold 82 which engagecorrespondinglyshaped openings 86 in the outer face of the rotary core17 to attain a more secure engagement between the key and the plug inthe course of its rotary movement. The recessed portions 83 of the keypermit the rotation of the key and the plugwhile the area designated Xin dotted lines in FIG. 6 of the outer face 15' of the lock is concealedby the armor plate surface 12. This area is the most vulnerable part ofthe lock for the introduction of drilling tools, which are capable ofdisabling the locking effects of the pin tumbler units. The shielding ofthe outer face of the lock at this vulnerable area supplements thesafety afforded by the use of pins of alloy steels within the lock,which are resistant to destruction by drilling tools.

The security of the locking mechanism is further enhanced by insuringagainst the destruction of the look by damaging the connections betweenthe lock mechanism and the bolt actuating mechanism, and particularly bydestroying the effectiveness of the tailpiece 18 extending between therotary core or plug 17 and the bolt actuating mechanism within the lockcase C. Protection against thisdamage is afforded by surrounding thecylindrical lock 15 with a tool resistant metallic shield 90 which isaffixed to the interior of the protrusion 11. A similar protectivecylinder 91, of tool resistant material, is affixed to the inner face ofattachment plate 60 onto which is affixed the lock case C. These datingdoors of different thicknesses. The provision of this protective shellaround the lock 15 and the connections extending therefrom precludes anapproach to the lock and its connection from beyond the area of thearmor plate 10 to effect its destruction.

The advantages of the invention may be realized in different degreesdepending upon the measure of security sought to be attained and thecharacter of the application of the lock assembly to the specific doorclosure. In the embodiment of the invention described above, a lockassembly is shown which requires the operation of the lock by a key,both from the inside as well as the outside of the door, so that even ifa burglar should succeed in entering the premises unlawfully by someother mode of ingress, such as a window, a rapid point of exit would bedenied him since the lock assembly, even from inside the premises, wouldbe substantially tamper-proof. However, the advantages of the inventionmay be realized to lesser degrees if the lock assembly is operated fromone side of the door to the exclusion of the other side, or if othermeans, such as a hand knob is used for controlling the lock on one side,as an adjunct to the operation of the lock from the opposite side by akey. Such arrangements are shown in the group of patents mentionedabove, and in such arrangements, a flat armor face plate could be usedon one side of the assembly with no keyhole therein.

Of course, if the alternate operation of the look by a handknob is notdesired, a safety lock may be attained which is operable only from theoutside by providing a flat closure plate for the lock assembly beyondthe bolt actuating mechanism. Such would be useful for inward openingdoors. as is the case with the arrangement described above. Such anarrangement with a blank flat plate may be used for operation by a keyfromthe inside only when the lock assembly is applied to back doors,where there is no need to admit people by key from the outside.

It is understood that the lock assembly may be constructed in manydifferent sizes to adapt the same for use inresidences as well as forlarger installations, in

r warehouses and other large enclosures.

cylinders are of slightly different diameter so that they 5 may interfitreciprocably for the purpose of accommo- We claim:

1. A burglar-proof lock assembly for mounting on a door within a doorframe having a strike mounted thereon provided with a pair of spacedapertured lugs projecting therefrom, comprising a. a lock case adaptedto be mounted on said door provided with slots in alignment with saidlugs for reception of said lugs in the closed condition of the doorwithin said frame, 4

b. a reciprocable locking bolt assembly in said case comprising a pairof coaxially disposed bolts for alternative engagement with theapertures in said lugs to interlock the door with the frame ordisengagement from said apertures to permit the separation of said doorfrom said frame,

c. an actuating mechanism within said case con- 'nected to said bolts,

d. an oscillating crank for operating said lastmentioned mechanism tocontrol the positioning of said bolts relative to said slots in saidlock case,

e. a cylinder lock comprising an outer barrel containing a plurality oflongitudinally arranged pin tumbler units, and an inner core having akeyhole at the outer end of said barrel and a tailpiece at the inner endthereof extending between said core and said oscillating crank,

f. a tool-resistant armor-plate displaced from said casing forsupporting said cylinder lock and concealing said cylinder lock andtailpiece, and

g. a frusto-conical protrusion on the front of said armor-plate forprotecting said lock against tampering and destruction, said armor-plateand protrusion having only a single opening of restrictd areaconstituted by a slot of restricted area, sufficient for the insertionof the shaft of the key adapted to be inserted in said keyhole and therotation thereof in said core while covering the outer face of thecylinder lock at the points thereof vulnerable to the entry of drills orother lock-picking and tampering tools.

2. A device as set forth in claim 1, including a second armor-platecovering the side of said lock case remote from said first-mentionedarmor-plate.

3. A device as set forth in claim 2, including screw fastening means forthe strike on the door frame adapted to extend into the heavy timberssupporting said door frame, said fastening means being concealed by saidlock case in the closed condition of the door.

4. A device as set forth in claim 3, wherein said screw fastening meanscomprises a plurality of wood screws ranging upwardly from two andone-half inches in length extending into the framing timbers from twotransverse directions.

5. A device as set forth in claim 1, including a protective enclosure oftool-resistant metal between said armor-plate and lock case surroundingsaid cylinder lock and tailpiece.

6. A device as set forth in claim 5, wherein said protective enclosurecomprises one cylindrical tube having one end projecting from theinterior of said protrusion and a second cylindrical tube, of slightlydifferent diameter from said first tube, having one end projecting fromsaid lock case, with the opposite free end of each cylindrical tubedisposed in overlapping telescopic relation.

7. A device as set forth in claim 1, including means for integratingsaid armor-plate with said lock case comprising a plurality of boltsintegrally connected to the inner face of said armor-plate and extendingthrough the door into said lock case, with fastening nuts on said boltsacting against the inner wall of said lock case.

8. A device as set forth in claim 3, including means for integratingsaid first-mentioned armor-plate with said lock case comprising aplurality of bolts integrally connected to the inner face of saidarmor-plate and extending through the door into said lock case, withfastening nuts on said bolts acting against the inner wall of said lockcase, said lock case and second armor-plate extending beyond the area ofattachment between said first armor-plate and lock case for engagementwith the lugs of the strike in the closed condition of the door, inwhich position said screw fastening means are covered by said case.

9. A device as set forth in claim 8, wherein said lock case is ofrectangular prismatic section defined by four rectangular wallsprojecting from the inner wall of said case, and said second armor-plateis detachably connected to the outer edges of said walls.

10. A device as set forth in claim 9, wherein the upper and lower wallsare provided with guide tracks at theouter edges thereof and reentrantflanges on the upper and lower edges of said second armor-plate forengaging said guide tracks for slidable movement thereon.

11. A device as set forth in claim 10, including a J- shaped extensionon said second armor-plate for encasing the outer lateral wall of saidcase and the exterior of the inner wall of said case adjacent thereto,and fastening bolts between the latter and said extension adjacent thefree extremity thereof for fixing said second armor-plate in closedposition on said case, said lastmentioned fastening bolts also beingconcealed at said strike.

12. A device as set forth in claim 11, wherein said J- shaped extensionis provided with slots complementing the slots in the lock case forreceiving the lugs of the strike in the closed condition of the doorwithin the frame.

13. A device as set forth in claim 7, wherein the displacement of thetool-resistant armor-plate from said casing corresponds to the thicknessof the door through which extend said plurality of bolts interconnectingsaid armor-plate and said lock case.

14. A burglar-proof lock assembly for mounting on an inwardly openingdoor within a door frame having a strike mounted thereon provided with apair of spaced apertured lugs projecting inwardly therefrom, comprisinga. a lock case adapted to be mounted on the inner side of said doorprovided with slots in alignment with said lugs for reception of saidlugs in the closed condition of the door within said frame,

b. a reciprocable locking bolt assembly in said case comprising a pairof coaxially disposed bolts for alternative engagement with theapertures in said lugs to interlock the door with the frame ordisengagement from said apertures to permit the separation of said doorfrom said frame,

0. an actuating mechansim within said case connected to said bolts,

d. an oscillating crank for operating said lastmentioned mechanism tocontrol the positioning of said bolts relative to said slots in saidlock case,

e. a cylinder lock comprising an outer barrel containing a plurality oflongitudinally arranged pin tumbler units, and an inner core having akeyhole at the outer end of said barrel and a tailpiece at the inner endthereof extending between said core and said oscillating crank,

f. a tool-resistant armor-plate displaced outwardly from said casing adistance corresponding substantially to the thickness of the door forsupporting said cylinder lock and concealing said cylinder lock andtailpiece,

g. a frusto-conical protrusion on the front of said armor-plate forprotecting said lock against tampering and destruction, said armor-plateand protru sion having only a single opening of restricted areaconstituted by a slot of restricted area, sufficient for the insertionof the shaft of the key adapted to be inserted in said keyhole and therotation thereof in said core while covering the outer face of thecylinder lock at the points thereof vulnerable to the entry of drills orother lock-picking and tampering tools,

h. a second tool-resistant armor-plate covering the side of said lockcase remote from said firstmentionedarmor-plate, and

i. a mechanical actuator extending through said second armor-plate andterminating within said lock case in a second rotary crank for operatingsaid first-mentioned actuating mechanism.

15. A device as setforth in claim 1, applied to an inwardly openingdoor, including a, a second tool-resistant armor-plate covering the sideof said lock case remote from said firstmentioned armor-plate,

b. a chamber with a frusto-conical exterior in said second armor-plateon the inner face of the door in substantial alignment with saidfrusto-conical protrusion in said first-mentioned armor-plate,

c. an indoor cylinder lock comprising an outer barrel containing aplurality of longitudinally arranged pin tumbler units and an inner corehaving a keyhole at the exposed end of said barrel and an oscillatingcrank connected to the inner end thereof for selective engagement withsaid bolt-actuating mechanism,

d. said second armor plate having a keyhole slot of restricted area inthe frusto-conical exterior of said chamber, said area being sufficientfor the insertion of the shaft of the key adapted to be inserted in saidkeyhole on the inner face of the door, and the rotation thereof in saidcore, while covering the outer face of said last-mentioned cylinder lockat the points thereof vulnerable to the entry of drills or otherlock-picking and tampering tools.

16. A device as set forth in claim 15, wherein the pin tumbler units inthe first-mentioned cylinder lock range from six to twelve in order torender the lock less vulnerable to picking tools.

17. A device as set forth in claim 15, wherein the pin tumbler units inboth of said cylinder locks range from six to twelve in order to renderthe lock less vulnerable to picking tools. 7 r

18. A device as set forth in claim 1, wherein said cylinder lock isprovided with a row of auxiliary pin tumbler units displaced angularlyon each side of said firstmentioned longitudinally arranged pin tumblerunits.

19. A device as set forth in claim 18, wherein the pin tumbler units inthe first-mentioned group range from six to twelve in order to renderthe lock less vulnerable to picking tools, and the auxiliary pin tumblerunits in the angularly displaced rows are diminished by at least one, atleast at one end of each row.

20. A device as set forth in claim 1, wherein the outer end of saidcylinder lock is affixed within the interior of said protrusionrearwardly of the front face of the latter to form a space therebetween,at least one apertured plate therebetween being of special alloyed metalto supplement the protection against tampering with the lock.

21. A device as set forth in claim 1, wherein the keyopening in saidarmor-plate is restricted substantially to the keyhole in the core ofthe cylinder lock, leaving unexposed the areas adjacent to the core ofspecial vulnerability to the destruction of the: pin tumbler units bydrilling or prying.

22. A device as set forth in claim 21, including a key bit with undercutindentations adjacent to the hand grip of the key to accommodate theouter face of said protrusion in the course of rotating the key.

23. A device as set forth in claim 22, whereinthe outer face of saidcore of the lock is provided with sockets for receiving propulsion pinson the handgrip of the key to reenforce the'coupling therebetween and tocompensate for the undercut indentations in the key. a:

1. A burglar-proof lock assembly for mounting on a door within a doorframe having a strike mounted thereon provided with a pair of spacedapertured lugs projecting therefrom, comprising a. a lock case adaptedto be mounted on said door provided with slots in alignment with saidlugs for reception of said lugs in the closed condition of the doorwithin said frame, b. a reciprocable locking bolt assembly in said casecomprising a pair of coaxially disposed bolts for alternative engagementwith the apertures in said lugs to interlock the door with the frame ordisengagement from said apertures to permit the separation of said doorfrom said frame, c. an actuating mechanism within said case connected tosaid bolts, d. an oscillating crank for operating said last-mentionedmechanism to control the positioning of said bolts relative to saidslots in said lock case, e. a cylinder lock comprising an outer barrelcontaining a plurality of longitudinally arranged pin tumbler units, andan inner core having a keyhole at the outer end of said barrel and atailpiece at the inner end thereof extending between said core and saidoscillating crank, f. a tool-resistant armor-plate displaced from saidcasing for supporting said cylinder lock and concealing said cylinderlock and tailpiece, and g. a frusto-conical protrusion on the front ofsaid armor-plate for protecting said lock against tampering anddestruction, said armor-plate and protrusion having only a singleopening of restrictd area constituted by a slot of restricted area,sufficient for the insertion of the shaft of the key adapted to beinserted in said keyhole and the rotation thereof in said core whilecovering the outer face of the cylinder lock at the points thereofvulnerable to the entry of drills or otHer lockpicking and tamperingtools.
 2. A device as set forth in claim 1, including a secondarmor-plate covering the side of said lock case remote from saidfirst-mentioned armor-plate.
 3. A device as set forth in claim 2,including screw fastening means for the strike on the door frame adaptedto extend into the heavy timbers supporting said door frame, saidfastening means being concealed by said lock case in the closedcondition of the door.
 4. A device as set forth in claim 3, wherein saidscrew fastening means comprises a plurality of wood screws rangingupwardly from two and one-half inches in length extending into theframing timbers from two transverse directions.
 5. A device as set forthin claim 1, including a protective enclosure of tool-resistant metalbetween said armor-plate and lock case surrounding said cylinder lockand tailpiece.
 6. A device as set forth in claim 5, wherein saidprotective enclosure comprises one cylindrical tube having one endprojecting from the interior of said protrusion and a second cylindricaltube, of slightly different diameter from said first tube, having oneend projecting from said lock case, with the opposite free end of eachcylindrical tube disposed in overlapping telescopic relation.
 7. Adevice as set forth in claim 1, including means for integrating saidarmor-plate with said lock case comprising a plurality of boltsintegrally connected to the inner face of said armor-plate and extendingthrough the door into said lock case, with fastening nuts on said boltsacting against the inner wall of said lock case.
 8. A device as setforth in claim 3, including means for integrating said first-mentionedarmor-plate with said lock case comprising a plurality of boltsintegrally connected to the inner face of said armor-plate and extendingthrough the door into said lock case, with fastening nuts on said boltsacting against the inner wall of said lock case, said lock case andsecond armor-plate extending beyond the area of attachment between saidfirst armor-plate and lock case for engagement with the lugs of thestrike in the closed condition of the door, in which position said screwfastening means are covered by said case.
 9. A device as set forth inclaim 8, wherein said lock case is of rectangular prismatic sectiondefined by four rectangular walls projecting from the inner wall of saidcase, and said second armor-plate is detachably connected to the outeredges of said walls.
 10. A device as set forth in claim 9, wherein theupper and lower walls are provided with guide tracks at the outer edgesthereof and reentrant flanges on the upper and lower edges of saidsecond armor-plate for engaging said guide tracks for slidable movementthereon.
 11. A device as set forth in claim 10, including a J-shapedextension on said second armor-plate for encasing the outer lateral wallof said case and the exterior of the inner wall of said case adjacentthereto, and fastening bolts between the latter and said extensionadjacent the free extremity thereof for fixing said second armor-platein closed position on said case, said last-mentioned fastening boltsalso being concealed at said strike.
 12. A device as set forth in claim11, wherein said J-shaped extension is provided with slots complementingthe slots in the lock case for receiving the lugs of the strike in theclosed condition of the door within the frame.
 13. A device as set forthin claim 7, wherein the displacement of the tool-resistant armor-platefrom said casing corresponds to the thickness of the door through whichextend said plurality of bolts interconnecting said armor-plate and saidlock case.
 14. A burglar-proof lock assembly for mounting on an inwardlyopening door within a door frame having a strike mounted thereonprovided with a pair of spaced apertured lugs projecting inwardlytherefrom, comprising a. a lock case adapted to be mounted on the innerside of said door provided with slots in alignment with said lugs forreceptiOn of said lugs in the closed condition of the door within saidframe, b. a reciprocable locking bolt assembly in said case comprising apair of coaxially disposed bolts for alternative engagement with theapertures in said lugs to interlock the door with the frame ordisengagement from said apertures to permit the separation of said doorfrom said frame, c. an actuating mechanism within said case connected tosaid bolts, d. an oscillating crank for operating said last-mentionedmechanism to control the positioning of said bolts relative to saidslots in said lock case, e. a cylinder lock comprising an outer barrelcontaining a plurality of longitudinally arranged pin tumbler units, andan inner core having a keyhole at the outer end of said barrel and atailpiece at the inner end thereof extending between said core and saidoscillating crank, f. a tool-resistant armor-plate displaced outwardlyfrom said casing a distance corresponding substantially to the thicknessof the door for supporting said cylinder lock and concealing saidcylinder lock and tailpiece, g. a frusto-conical protrusion on the frontof said armor-plate for protecting said lock against tampering anddestruction, said armor-plate and protrusion having only a singleopening of restricted area constituted by a slot of restricted area,sufficient for the insertion of the shaft of the key adapted to beinserted in said keyhole and the rotation thereof in said core whilecovering the outer face of the cylinder lock at the points thereofvulnerable to the entry of drills or other lock-picking and tamperingtools, h. a second tool-resistant armor-plate covering the side of saidlock case remote from said first-mentioned armor-plate, and i. amechanical actuator extending through said second armor-plate andterminating within said lock case in a second rotary crank for operatingsaid first-mentioned actuating mechanism.
 15. A device as set forth inclaim 1, applied to an inwardly opening door, including a. a secondtool-resistant armor-plate covering the side of said lock case remotefrom said first-mentioned armor-plate, b. a chamber with afrusto-conical exterior in said second armor-plate on the inner face ofthe door in substantial alignment with said frusto-conical protrusion insaid first-mentioned armor-plate, c. an indoor cylinder lock comprisingan outer barrel containing a plurality of longitudinally arranged pintumbler units and an inner core having a keyhole at the exposed end ofsaid barrel and an oscillating crank connected to the inner end thereoffor selective engagement with said bolt-actuating mechanism, d. saidsecond armor plate having a keyhole slot of restricted area in thefrusto-conical exterior of said chamber, said area being sufficient forthe insertion of the shaft of the key adapted to be inserted in saidkeyhole on the inner face of the door, and the rotation thereof in saidcore, while covering the outer face of said last-mentioned cylinder lockat the points thereof vulnerable to the entry of drills or otherlock-picking and tampering tools.
 16. A device as set forth in claim 15,wherein the pin tumbler units in the first-mentioned cylinder lock rangefrom six to twelve in order to render the lock less vulnerable topicking tools.
 17. A device as set forth in claim 15, wherein the pintumbler units in both of said cylinder locks range from six to twelve inorder to render the lock less vulnerable to picking tools.
 18. A deviceas set forth in claim 1, wherein said cylinder lock is provided with arow of auxiliary pin tumbler units displaced angularly on each side ofsaid first-mentioned longitudinally arranged pin tumbler units.
 19. Adevice as set forth in claim 18, wherein the pin tumbler units in thefirst-mentioned group range from six to twelve in order to render thelock less vulnerable to picking tools, and the auxiliary pin tumblerunits in the angularly displaced rows are diminished by at least one, atleasT at one end of each row.
 20. A device as set forth in claim 1,wherein the outer end of said cylinder lock is affixed within theinterior of said protrusion rearwardly of the front face of the latterto form a space therebetween, at least one apertured plate therebetweenbeing of special alloyed metal to supplement the protection againsttampering with the lock.
 21. A device as set forth in claim 1, whereinthe key-opening in said armor-plate is restricted substantially to thekeyhole in the core of the cylinder lock, leaving unexposed the areasadjacent to the core of special vulnerability to the destruction of thepin tumbler units by drilling or prying.
 22. A device as set forth inclaim 21, including a key bit with undercut indentations adjacent to thehand grip of the key to accommodate the outer face of said protrusion inthe course of rotating the key.
 23. A device as set forth in claim 22,wherein the outer face of said core of the lock is provided with socketsfor receiving propulsion pins on the handgrip of the key to reenforcethe coupling therebetween and to compensate for the undercutindentations in the key.